Semiconductor electronic devices have internal losses which generate heat. When the electronic device is configured for a substantial amount of power, cooling is necessary in order to limit the semiconductor device to a sufficiently low temperature to provide a reasonable life. Power modules containing this type of semiconductor component are traditionally attached to a cold plate. The cold plate may have fins thereon with circulation of fluid therepast. The fluid is usually liquid when greater amounts of heat must be dissipated.
When semiconductor electronics are operated under steady-state conditions, heat flow and maximum temperatures at critical points can be readily controlled by such systems. However, some semiconductor power modules are subjected to periodic high-power cycles which must be limited in order to maintain the semiconductor device temperature within the acceptable range for that device. The reduction of upward temperature excursions increases the reliability of the semiconductor device by decreasing the thermally induced stress within the power module. Thus, there is need for an improved cooling structure by which semiconductor devices can have their peak temperature limited when subjected to intermittent major current loads.